Electromagnetic switching device



W. WILLENBRUCH.

ELECTROMAGNETIC SWITCHING DEVICE.

APPLICATION FILED DEC. 30. 1916.

1,330,507. Patented Feb. 10, 1920.

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WALTHER WILLENBRUCH, OF NEW YORK, N. Y., ASSIGNOR- TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK ELECTROMAGNETIC "SWITCHING- DEVICE.

Specification of Letters Patent.

Patented Feb. 10, 1920.

Application filed December 30, 1916. Serial No. 139,877.

This invention relates ,to electromagnetic switching devices, its object being to provide an electromagnetic switching device or relay which is slow in releasing, and which is simple in construction and positive in action.

In accordance with one feature of this invention, an electromagnetic relay is constructed with a secondary source of current in shunt with a main energizing element. In the preferred embodiment an electrolytic cell and a regulating resistance, connected in series therewith, are connected in shunt of an energizing wlnding of the relay or 'a portion of such winding. v

The nature of this invention will be more clearly seen by reference to the drawing, in which Figure 1 shows schematically one embodiment of the invention suitable forhigh voltage relays; and Fig. 2another, suitable.

for low voltage servic Corresponding arts in the two figures of the drawing are designated by the same reference symbols.

Referring now tothe drawing, 5 is an elec- I tromagnetic relay comprising a core 8, an energizing winding 9, an armature-10 and a contact 11. The armature 10 is normally out of engagement with contact 11, but this arrangement is not essential to this inven' tion, since contact 11 could as well be so positioned that armature 10 would normally be in engagement therewith. The relay 5 is then shown connected in a main circuit with a battery 12 and a key 13. In shunt with a portion of the winding 9 ofrelay 5 in Fig. 1,

- and ll of the winding 9 in Fig.- 2, is connected an electrolytic cell 6 and a regulating re sistance 7.

Theelectrolytic cell 6 may of any well-- known type which is capable of reacting to an electric current so as to produce a counter-electromotive force for a finite period of time after the discontinuance of the ehargingcurrent. The preferred construo tion, however, is shown in the drawing, in which two platinum. electrodes 14, 14 are sealed into a glass container 15, which is, partly filled with an electrolyte 16 of dilute sulfuric acid.

It is believed that the "invention will be clearly understood from a description of the operation of the schemes, shown in the'drawing, and it will be so described.

It will be assumed that the relay 5' has been actuated by the closure of the main circuit at the key 13, so that the armature 10 is in its attracted position and in engage ment with contact 11. Under these conditions a certain value. of current is flowing through the winding 9, and there is a corresponding diflerence of potential between the terminal points 17 and 18 of the shunt in eluding the electrolytic cell 6 and the regulating resistance 7. By the proper location of the terminal point 17 by the suitable con:

struction of the electrolytic cell 6, or by the rightadjustment of the resistance 7, the corresponding potential across the terminals of the electrolytic cell 6 can be made of such a value that a charging current will pass be-- tween the electrodes 14, 14. Due to this current, the cell will bepolarized and will be maintained in this condition 'as long as the main circuit remains closed.

Assuming now that the main circuit; is

opened at key 13, the relay 5 ordinarily would become immediately deenergized and the armature 10 would at once return to its normal position, but, due to the cooperation of the elements in accordance with this invention, the polarization of the electrodes 14, 1 4, hereinbefore mentioned, causes the electrolytic cell to furnish a reverse flow of current, which passes-through the portion of the wlnding between terminal points 17 and 12} the same direction as the main energlzlng current. This current will continue or a finite period of time, and, so long as -it is at least as large as the minimum current necessary tohold the armature 10 in attracted P08113011, the relay will not release. Dependmg upon the construction of the electrolytic cell 6, the value of resistance 7, the

portion of thegwinding between terminal po nts 17 and 18,-and the adjustment of the relay, the time required for the discharge. current tofall below the minimum holding yalue of current for the relay will be determined. p

In the preferred construction of the electrolytic cell, as shown in the drawing and hereinbefore described, the amount of the discharge current due to the polarization of the platinum electrodes is of a fairly fixed value, regardless-of the length of time that the charging voltage is applied. Therefore,

when such a cell is combined in a circuit with a given relay and regulating resistance, the time of release of that relay will be fixed and uniform,a necessary condition for satisfactory operation.

What is claimed is:

1. In combination, a relay, an energizing Winding therefor, a source of energizing current adapted to be associated with and disassociated from the Winding, and a polarization cell permanently shunting a portion of the Winding to store energy upon the association of the source with the winding and to dissipate such energy through such portion, thereby delaying the deenergization thereof for a time interval determlned by ization cell to store energy for a prede' termined time upon the association of the source-With the Winding and to dissipate such energy through the Winding upon the subsequent disassociation of the. source he;

reactor from to delay the decnergization thereof forassociated from the winding, and a polarization cell associated with the winding adapted to store energy upon the association of the source with the winding and to dissipate such energy through the winding upon the subsequent disassociation of the source therefrom to delay the deenergization thereof for a definite period determined by the amount of energy stored.

&. In combination, a relay, an energizing winding therefor, a source of energizing current adapted to be associated with and disassociated from the Winding, and a polarization cell associated with the winding to store energy upon the association of the source with the winding and to dissipate such energy through the winding upon the disassociation of the source from the winding to delay the deenergization thereof.

in witness whereof, I hereunto subscribe my name this 29th day of December A. D., 1915.

iViLTl-IER WILLENBRUCH. 

